All movies starring Pauly Shore

The world goes backwards on Opposite Day. The kids become adults, and the adults become kids.

Stoney and Dave find a caveman (Link) trapped in ice, thaw him out, and show him around town. Although Link is slow to catch on to basic concepts of 20th century life, he has no trouble impressing all the girls and helping Stoney and Dave find the coolness they've been searching for.